bluetooth: android: Fix a couple of crashes when adapter is turned on/off.

device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.device.bluetooth;
 
 import android.Manifest;
 import android.annotation.TargetApi;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
@@ skipping 28 matching lines @@
  *
  * Each Wrapper base class accepts an Android API object and passes through
  * calls to it. When under test, Fake subclasses override all methods that
  * pass through to the Android object and instead provide fake implementations.
  */
 @JNINamespace("device")
 @TargetApi(Build.VERSION_CODES.LOLLIPOP)
 class Wrappers {
     private static final String TAG = "Bluetooth";
 
+    public static final int DEVICE_CLASS_UNSPECIFIED = 0x1F00;
+
     /**
      * Wraps android.bluetooth.BluetoothAdapter.
      */
     static class BluetoothAdapterWrapper {
         private final BluetoothAdapter mAdapter;
         protected final ContextWrapper mContext;
-        protected final BluetoothLeScannerWrapper mScanner;
+        protected BluetoothLeScannerWrapper mScannerWrapper;
 
         /**
          * Creates a BluetoothAdapterWrapper using the default
          * android.bluetooth.BluetoothAdapter. May fail if the default adapter
          * is not available or if the application does not have sufficient
          * permissions.
          */
         @CalledByNative("BluetoothAdapterWrapper")
         public static BluetoothAdapterWrapper createWithDefaultAdapter(Context context) {
             final boolean hasMinAPI = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP;
@@ skipping 21 matching lines @@
             if (!hasLowEnergyFeature) {
                 Log.i(TAG, "BluetoothAdapterWrapper.create failed: No Low Energy support.");
                 return null;
             }
 
             BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
             if (adapter == null) {
                 Log.i(TAG, "BluetoothAdapterWrapper.create failed: Default adapter not found.");
                 return null;
             } else {
-                return new BluetoothAdapterWrapper(adapter, new ContextWrapper(context),
-                        new BluetoothLeScannerWrapper(adapter.getBluetoothLeScanner()));
+                return new BluetoothAdapterWrapper(adapter, new ContextWrapper(context));
             }
         }
 
-        public BluetoothAdapterWrapper(BluetoothAdapter adapter, ContextWrapper context,
-                BluetoothLeScannerWrapper scanner) {
+        public BluetoothAdapterWrapper(BluetoothAdapter adapter, ContextWrapper context) {
             mAdapter = adapter;
             mContext = context;
-            mScanner = scanner;
+        }
+
+        public String getAddress() {
+            return mAdapter.getAddress();
+        }
+
+        public BluetoothLeScannerWrapper getBluetoothLeScanner() {
+            BluetoothLeScanner scanner = mAdapter.getBluetoothLeScanner();
+            if (scanner == null) {
+                return null;
+            }
+            if (mScannerWrapper == null) {
+                mScannerWrapper = new BluetoothLeScannerWrapper(scanner);
+            }
+            return mScannerWrapper;
         }
 
         public ContextWrapper getContext() {
             return mContext;
         }
 
-        public BluetoothLeScannerWrapper getBluetoothLeScanner() {
-            return mScanner;
-        }
-
-        public boolean isEnabled() {
-            return mAdapter.isEnabled();
-        }
-
-        public String getAddress() {
-            return mAdapter.getAddress();
-        }
-
         public String getName() {
             return mAdapter.getName();
         }
 
         public int getScanMode() {
             return mAdapter.getScanMode();
         }
 
         public boolean isDiscovering() {
             return mAdapter.isDiscovering();
         }
+
+        public boolean isEnabled() {
+            return mAdapter.isEnabled();
+        }
+
+        public boolean setPowered(boolean powered) {

[scheib, 2016/02/05 18:06:19]

The wrapper should mimic the Android API as closely as possible, such that one
could replace the wrapper instance in the code that uses it with the system
Adapter type and have it compile and work. Please expose wrapper methods for
enable/disable instead of 'setPowered'. 

[perja, 2016/02/08 14:48:31]

Done.

+            if (powered) {
+                return mAdapter.enable();
+            } else {
+                return mAdapter.disable();
+            }
+        }
     }
 
     /**
      * Wraps android.content.Context.
      */
     static class ContextWrapper {
         private final Context mContext;
 
         public ContextWrapper(Context context) {
             mContext = context;
         }
 
         public boolean checkPermission(String permission) {
             return mContext.checkPermission(permission, Process.myPid(), Process.myUid())
                     == PackageManager.PERMISSION_GRANTED;
         }
     }
 
     /**
      * Wraps android.bluetooth.BluetoothLeScanner.
      */
     static class BluetoothLeScannerWrapper {
-        private final BluetoothLeScanner mScanner;
+        protected final BluetoothLeScanner mScanner;
         private final HashMap<ScanCallbackWrapper, ForwardScanCallbackToWrapper> mCallbacks;
 
         public BluetoothLeScannerWrapper(BluetoothLeScanner scanner) {
             mScanner = scanner;
             mCallbacks = new HashMap<ScanCallbackWrapper, ForwardScanCallbackToWrapper>();
         }
 
         public void startScan(
                 List<ScanFilter> filters, int scanSettingsScanMode, ScanCallbackWrapper callback) {
             ScanSettings settings =
                     new ScanSettings.Builder().setScanMode(scanSettingsScanMode).build();
 
             ForwardScanCallbackToWrapper callbackForwarder =
                     new ForwardScanCallbackToWrapper(callback);
             mCallbacks.put(callback, callbackForwarder);
-
             mScanner.startScan(filters, settings, callbackForwarder);

[scheib, 2016/02/05 18:06:19]

Leave the blank line.

[perja, 2016/02/08 14:48:31]

Done.

         }
 
         public void stopScan(ScanCallbackWrapper callback) {
             ForwardScanCallbackToWrapper callbackForwarder = mCallbacks.remove(callback);
             mScanner.stopScan(callbackForwarder);
         }
     }
 
     /**
      * Implements android.bluetooth.le.ScanCallback and forwards calls through to a
@@ skipping 83 matching lines @@
                     mDevice.connectGatt(context, autoConnect,
                             new ForwardBluetoothGattCallbackToWrapper(callback, this)),
                     this);
         }
 
         public String getAddress() {
             return mDevice.getAddress();
         }
 
         public int getBluetoothClass_getDeviceClass() {
+            if (mDevice == null || mDevice.getBluetoothClass() == null) {
+                // BluetoothDevice.getBluetoothClass() returns null if adapter has been powered off.
+                // Return DEVICE_CLASS_UNSPECIFIED in these cases.
+                return DEVICE_CLASS_UNSPECIFIED;
+            }
             return mDevice.getBluetoothClass().getDeviceClass();
         }
 
         public int getBondState() {
             return mDevice.getBondState();
         }
 
         public String getName() {
             return mDevice.getName();
         }
@@ skipping 243 matching lines @@
 
         public byte[] getValue() {
             return mDescriptor.getValue();
         }
 
         public boolean setValue(byte[] value) {
             return mDescriptor.setValue(value);
         }
     }
 }